1. Field of the Invention
This invention relates to a torque balancer used in, for instance, inclinometers, angular accelerometers or the like.
2. Description of the Prior Art
A conventional inclinometer using a torque balancer has the following construction. Specifically, an unbalanced weight is attached to a movable coil of a zero-balance ammeter, and a feedback current is fed to the movable coil in a direction for cancelling torque caused by the weight when the inclinometer is inclined. For this end, relative declination of the movable coil is detected and connected to an electrical signal by a relative declination detector, and the electrical signal, after amplified, is supplied to the movable coil as a negative feedback signal.
The conventional torque balancer, however, incurs a problem in that is not possible to obtain a feedback signal satisfying both a large balanceable torque range (large measurable inclination range in case of a inclinometer) and a high response speed. More specifically, the conventional torque balancer is configured to generate a balanced magnetic field corresponding to the operative range of an inclinometer either in a circuit with a magnet outside a coil or in a circuit with a magnet inside the coil. This results in a substantially uniform magnetic field which is widely and uniformly distributed over a relatively large movable range of the movable coil and hence results in a low magnetic flux density. As a result, sufficient feedback torque is not produced, the balanceable torque range is small, and the response speed is slow. Further, the entire apparatus is necessarily large-scaled in the attempt to obtain a large movable range of the movable coil.